MAKING AND CURING CONCRETE CUBES AS PER IS:516-1959

MAKING AND CURING CONCRETE CUBES AS PER IS:516-1959

OBJECTIVES:                                                                                                        

This method covers the procedure or making and curing of concrete cubes as per IS: 516- 1959.                                                                                   

                

APPARATUS:                                                                                                         

Wheelbarrow, sampling scoop, trowel, cube mould of 15x15x15 cm size and tamping bar 16mm in diameter, 0.6 m long and bulleted point at the lower end.                                                                        

PROCEDURE:                                                                                                        

1. Decide the number of samples to be taken during concreting (as per table no. 15.2.2 of IS: 456-2000)                                                                                                  

2. Oil the interior surface of the mould with a mould releasing oil to prevent adhesion of concrete.                                                                                                 

3. Collect the sample in a wheelbarrow after mixing the concrete properly in the transit mixture.                                                                                                  

4. Remix the sample thoroughly in a wheelbarrow with sampling scoop.                                                                                                       

5. After remixing immediately fill the mould in layers approximately 5 cm deep.                                                                                                   

6. During filling the mould, the scoop shall be moved around the top edge of the mould as the concrete slides from it in order to ensure a symmetrical distribution of the concrete within the mould.                                                                                                      

7. Each layer shall be compacted with the tamping rod by minimum 35 strokes distributed in a uniform manner over the cross-section of the mould.                                                                                                  

8. After compacting the top layer, the top surface of the concrete shall be finished level with the top of the mould using a trowel.                                                                                                            

9. Store the cube moulds in a place which is free from vibration and cover the surface of the concrete with a piece of damp sacking for initial 16 to 24 hours.